D2D communication refers to a communication mode in which enables a UE for D2D to directly perform data communication, without the help of a cellular network, when the UE has discovered a UE of interest to be adjoined thereto.
Communication providers are attempting to create profit by providing D2D communication utilizing an allowed frequency band unused thereby or wireless resources non-allocated to a cellular network and the like. Therefore, a method for providing D2D communication and controlling a D2D service on the basis of a cellular network has been sought.
However, since a UE for D2D must identify whether or not counterpart UEs of interest are adjoined thereto or the like, a method for discovering the counterpart UEs of interest is required for D2D communication. In this case, in order to discover a counterpart UE without using a cellular network, each UE for D2D must continuously broadcast its own information to the vicinities thereof and receive information broadcasted by adjacent UEs for D2D, so that much power consumption is predicted.
Therefore, for more efficient D2D communication, a method for discovering a counterpart UE for D2D of interest with reduced power consumption by using a cellular network is required.